Enabling healthcheck on the default pool of the L4 virtual server with sorry pool in NSX-T

Products

• VMware NSX

Issue/Introduction

Symptoms:

• If an L4 virtual server has both default pool and sorry pool, if the default pool has no monitor enabled, the traffic would never be re-dispatched to the sorry pool.
• Even if the backend servers on default pool are powered off or service disabled, the LB would still treat the server as UP due to no active or passive monitor enabled on that pool.

Environment

VMware NSX-T Data Center

Resolution

To resolve this issue, enable either active monitor or passive monitor on the default pool so that the L4 virtual server can re-dispatch the traffic to the sorry pool if no servers on default pool are available.

Note: Even for L7 virtual server, it is also recommended to enable monitor on the default pool so that load balancer will not retry every default backend servers for each HTTP request so that the traffic could be re-dispatched to sorry pool.